Fluidic weighing and sorting system



United States Patent Inventor Chris E. Spyropoulos Washington, D.C.

Appl. No 806,482

Filed Mar. 12, 1969 Patented Dec. 29, 1970 Assignee The United States ofAmerica as represented by the Secretary of the Army FLUIDIC WElGHING ANDSORTING SYSTEM 5 Claims, 3 Drawing Figs.

US. Cl. 209/121 Int. Cl B07c 5/16 209/74,

Field of Search 120, 121; l77/(Inquired) [56] References Cited UNITEDSTATES PATENTS 3,317,039 5/1967 Wadey 209/l2lX 3,369,661 2/l 968Bradshaw 209/12 lX Primary Examiner-Richard A Schacher An0rneysHarry M.Saragovitz, Edward J. Kelly, Herbert Berl and J. D. Edgerton ABSTRACT: Afluidic system for weighing and sorting items transported along a mainguide path into a plurality of groups. A predetermined velocity isimparted to the item, which is then acted upon by a retarding means toslow down the item at a rate proportional to the weight of the item. Theitem actuates a delay means which in turn operates a switching meanscausing items of a first weight to be diverted into a branch guide whileall other items continue down the main guide.

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sum 2 OF 2 IN vE HToR This invention relates to systems for sortingitems such as cards, letters and other like items into a plurality ofweight groups. Such systems typically employ mechanical parts moving athigh speeds to handle and transport the items. Whenever highspeedmechanical action is involved, there is always the problem ofbreakdown of the moving parts or damage to the items caused by jammingor mishandling.

SUMMARY OF THE INVENTION The present invention avoids the problems ofconventional systems by providing a flueric system which operateswithout moving mechanical parts in the sensing, logic and gatingfunctions. The system comprises a main guide path along which items arecarried by fluid flow. The items are launched in the path at apredetermined velocity by pinch rollers turning at a predeterminedvelocity. A branch guide path is located downstream of the pinch rollersa predetermined distance. As an item leaves the pinch rollers, slowdownjets are energized to exert a uniform fixed force over the same exposedlength of each item, thereby retarding the item at a rate proportionalto the weight of the item.

A switching fluid amplifier is located adjacent the branch guide path toswitch items of a first weight into the branch guide path in accordancewith signals received from a delay means and to allow all other items topass along the main guide. The delay means in one embodiment of theinvention includes a timer control and in a second embodiment includes adelay line. The delay means is energized by item sensing means locatedin the main guide path.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic view of onesystem embodiment of the invention;

FIG. 2 is a diagrammatic cross-sectional view taken along line 2-2 ofFIG. 1; and

FIG. 3 is a diagrammatic view of a second system embodiment of theinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagrammatic viewof one system constructed in accordance with the present invention; andFIG. 2 is a diagrammatic cross-sectional view taken along line 22 ofFIG. I. A plurality of spaced items I and 3 are shown being transporteddown a main guide path 5 which has a branch guide path 7 joined thereto.Pairs of pinch rollers 9 and 11 are located in main guide 5 to engagethe items being transported and impart a predetermined fixed velocitythereto. Spaced from pinch rollers 11 at a distance less than the lengthof any given item to be transported are sensing ports 13 and 15, andretarding jet nozzles 17 and 19. Sensing ports 13 and receive theirinputs from fluid flow through control lines M and 23, respectively.

Biased fluid amplifiers 25 and 27 are conventional devices in which amain input at 29 normally produces an output on line 31 in the absenceofa bias input on line 33. When a bias input is present on line 33, maininput 29 is diverted to output line 35 and remains there until biasinput 33 is removed, whereupon the output will switch to line 31. Suchelements are conventional in the art and their operation need not bediscussed further.

Output line 35 of amplifier 25 is connected to the start input of delaycontrol means 37. This delay control means 37 is a timer having outputlines 39 and 41 which form the control inputs to the bistable memoryamplifier 43. Amplifier 43 is located at the junction of main guide 5and branch guide 7.

When output line 45 of amplifier 43 is' energized, diverting nozzle 49will cause any item passing along main guide 5 to be diverted intobranch guide 7. Diverting nozzle 49 is turned on by an input from line39 and remains on until an input is obtained from line 41 to causebistable amplifier 43 to switch to output 47 and be exhausted to theatmosphere or otherwise disposed of.

The retarding jet nozzles 17 and 19 are energized by bistable amplifier51 which is switched by inputs on control lines 53 and 55. Retardingjets 17 and 19 are turned on by an output on line 55 from amplifier 27.This output occurs whenever sensing port 15 is blocked by an itemproceeding down main guide 5. Retarding jets 17 and 19 are turned off byan input on line 53, which is energized by amplifier 27 through output57 when there is a bias input from sensing port 15 caused by no itembeing present in that particular portion of main guide 5. Output 57 ofamplifier 27 also sets to zero the delay control timer 37, therebypreventing any output on lines 39 or 41.

As the system begins operation, sensing ports 13 and 15 areunobstructed, thereby causing outputs on lines 35 and 57 of amplifiers25 and 27, respectively. This means that the start input to delaycontrol timer 37 is enabled, but since zero input line 57 is alsoenabled, there is no usable output from the timer. When item 1 moves tothe right down guide 5 and blocks both sensing ports 13 and 15,amplifiers 25 and 27 are switched so that timer 37 has no input eitherto the start or zero input lines. When amplifier 27 is switched tooutput line 55, bistable amplifier 51 is switched to turn-on retardingjets l7 and 19 which act against the motion of card I being imparted bypinch rollers ll. As the trailing edge of card 1 uncovers sensing port13, amplifier 25 will be switched back to an output on line 35, therebystarting timer 37. At this time zero input line 57 is not enabled so anoutput is obtained on line 39 of timer 37 to switch bistable amplifier43 to output line 45 and energize diverting nozzle 49. There is apredetermined time interval in timer 37 between the occurrence of anoutput on line 39 before an output will appear on line 41. This timeinterval must be less than the time required for the trailing edge ofany given item to travel from pinch rollers 11 to sensing port 15. Anyitems passing nozzle 49 during the interval after output line 39 isenergized, but before line 41 is energized, will be diverted down branchguide 7. It is the action of retarding jets l7 and 19 that determineswhich items will be the transported item, the rate of decrease being afunction of the weight of the item. The flow rate and the velocity ofthe retarding jets are fixed, and all items travel at a constantvelocity as they are released from the pinch rollers. Since the lengthof the item acted upon by the retarding jets is fixed at the distancebetween the pinch rollers 11 and the retarding jets l7 and 19, the rateof decrease of velocity of the items is primarily a function of theitems weights. By choosing the interval of time between outputsoccurring on line 39 and 41 the cutoff weight can be determined foritems that are to be allowed to proceed down main guide 5. Since itemshaving greater weight will be less affected by the action of retardingjets l7 and 19 and therefore arrive at branch guide 7 in a shorter timethan the lighter items, the continuation of main guide 5 will carry thelighter items, with the heavier items being diverted into branch guide7.

When the first item I has cleared both of the sensing ports 13 and 15there will again be inputs to the start and zero terminals of timer 37resulting in no output from timer 37. Diverting nozzle 49 may be off oron depending upon whether or not item I was lighter than the requiredweight to be diverted into branch guide 7 or whether item 1 was divertedinto branch guide 7. The condition of diverting nozzle is immaterial,since the next succeeding item will produce a start input to timer 37when the trailing edge of the item clears sensing port 13, therebyenergizing line 39 to divert the output of bistable amplifier 43 todiverting nozzle 49, if the output was not already present there. Thesequence of logical operations on succeeding items proceeds in the samemanner as that described in connection with item 1, until all of theitems have been sorted.

A second embodiment of the invention is shown in FIG. 3

- where like components have been shown with like numbers. "The sensingand gating functions'are the same as those described in connection withthe system of H6. 1 and will not be repeated here. The logic forcontrolling the operation is different, however, and the descriptionwill be devoted to the operation of the logic.

Prior to item 1 entering the main guide path 5, sensing ports 1 13 and15 are unobstructed and there is flow in lines 61 and 63 to AND gate 65.AND gate 65 is constructed such that an '71 which is also an input lineto AND gate 73; An input on line 71 to AND gate 73 causes an output online 75 which is exhausted and not utilized. When item 1 interrupts theflow through sensing port 13, AND gate65 switches to output line 69,thereby switching bistable memorya'mplifier 43 to its exhaust output ifit were not already insuch state. As item 1 blocks sensing port 15 bothinputs toAND gate 65 are shut 1 off, but this produces no change in thecontrol logic.

-When the trailing edge of item 1 clears sensing port 13, input line 61is energized and produces an output on line 67 of AND gate 65. Thisaction causes an input to bistable amplifier 51 on line 81 and turns onthe retarding jets l7 and 19 which .had previously been shut off whenoutput line 71 of AND gate "65 was energized. The output on line 67also-passes through delay line 83 toAND gate 73 where it produces anoutput on line. Fluid fiow in line 77 causes memory amplifier 43 toswitch and energize diverting nozzle 49 if there is no input on line 71.

Let it be assumed that item 1 is light enough in weight so -.thatretarding jets 17 and 19 slow down its forward progress and cause item 1to exceed a predetermined interval between the trailing edge leavingpinch rollers 11 and clearing sensing port 15. In this case the input online 63 caused by item 1 clearing sensing port 15 will cause AND gate 65to switch to an output on line 71. AND gate 73 will therefore beswitched away from output 77, but this action. will have occurred toolate to prevent output 77 from having switched memory amplifier 43 toenergize diverting nozzle 49. Since diverting nozzle 49 has beenenergized, then the light item will be diverted into branch guide 7.

- Next, let it be assumed that item 1 is sufficiently heavy so thatretarding jets 17 and 19 do not slow the item down and {cause the itemto exceed the predetermined interval between I trailing edge of item 1leaving pinch rollers 11 and arriving at sensing port 15. The input toAND gate 65 on line 63 produced by the trailing edge of item 1 clearingsensing port 15.will energize AND gate 73 through output line 71. The.predetermined interval referred to is controlled by the delay caused bydelay line 83. if line 71 is energized prior to a pressure wave or fluidin line 67 passing through the required delay interval of delay line 83and arriving at AND gate 73, therl AND gate 73 will produce an output online 75. Upon arrival of fluid through delay line 83, AND gate 73'willbe switched to an output on line 76', but in no case will an output beproduced on line 77 to switch memory amplifier 43 and energizeddiverting nozzle 49. This action allows'it em 1 to pass straight downguide path 5 and not be diverted into branch guide 7. 1 1

It will be appreciated that the amount of'del ay'in delay line 83 willbe the controlling factor as to the'cutoff point in item weight betweenthose items diverted into branch guide 7 and those allowed to pass alongguide path means 5. By designing the delay line to have the desireddelay, the weight factor in the sorting processmay be determined.

lclaim: 1. A fiuenc weighing and sorting devicefor sorting items into aplurality of weight groups comprising:

a main guide path;

means for launchingitems in said main guide path with a predeterminedvelocity;

a branch guide path located downstream a predetermined distance fromsaid launching means;

means for retarding the velocity of an item at a rate proportional tothe weight of the item;

switching means for diverting items from said main guide path into saidbranch guide path;

.delay means for actuating said switching means; and

sensing means in said main guide path adjacent said launching means forcontrolling said retarding means and said delay means; whereby items ofa first weight will be diverted into said branch guide while all otheritems will continue down said main guide path. l 2. The combinationaccording to claim 1 wherein said means for launching comprises aplurality of pinch rollers turning at a constant predetermined velocity.

3. The combination according to claim 1 wherein said means for retardingcomprises fluid jet means directed against opposite sides of an itemwith a predetermined force and over a predetermined length of said item.

4. The combination according to claim 1 wherein said delay meanscomprises:

a timer energized by said sensing means to produce a delayed outputwhich turns off said switching means;

whereby any' item arriving at said branch guide path thereafter willcontinue along saidmain guide path and not be diverted.

5. The combination according to claim 1 wherein said delay meanscomprises:

a delay line energized by said sensing means to produce a' delayedoutput which turns on said switching means,

whereby an item arriving at saidbranch guide path

